SMTP=E2=80=99s simplicity causes it to be a relatively vulnerable proto=
col. Spammers who send email messages with falsified headers often abuse it=
.

Make certain that you define the system's SMTP options=
. They help spam attacks on and from your server. Spammers can send many sp=
am messages within a short period of time, which use a large amount of your=
server's bandwidth.

We strongly recommend that you use the B=
asic Editor and Advanced Editor interfaces to make changes to your=
Exim configuration. Do not modify the Exim configuration =
files manually.

The /etc/exim.conf.local file does not exi=
st by default. The system creates the /etc/exim.conf.local fil=
e after you configure Exim's settings to use non-default v=
alues.

For custom ACL changes to the Exim configuration, the system creates a =
file in a subdirectory under the /usr/local/cpanel/etc/exim/acls/ directory. For example, if you create a custom acl_smtp_helo_bloc=
k entry, the system stores the setting in the /usr/local/cpane=
l/etc/exim/acls/ACL_SMTP_HELO_BLOCK/custom_begin_smtp_helo file.

To skip RBLs for specific domains, log in as the root user =
and use your preferred text editor to create and edit the /etc/skiprb=
ldomains file.

Add the domains to the file, with one domain name per line.

After you create the /etc/skiprbldomains file, enable the =
skip_rbl_domains directive.

Warning:

cPanel & WHM uses the following directives in its Mail SNI integrati=
on:

tls_privatekey

tls_certificate

tls_verify_certificates

If you manually change any of these directives, you may break Mail SNI i=
ntegration in cPanel & WHM.

To set up smarthost authentication for a specific domain, enter the foll=
owing lines in the AUTH section: